Flood warnings are in effect for Dodge, Jefferson, Rock and Winnebago counties through the week.
The National Weather Service has issued flood warnings for four counties in southeast Wisconsin as two major waterways push past their flooding thresholds. The alerts, issued Tuesday, May 5, come as both Rock River and Lake Koshkonong remain at minor flooding stages, with conditions expected to persist through much of the week before any meaningful improvement arrives.
Residents in the affected areas are urged to stay alert, avoid any contact with floodwaters and monitor official updates closely as forecasters track what is expected to be a slow but steady decline in water levels over the coming days.
The 4 counties under warning
The flood warnings cover four southeast Wisconsin counties: 1) Dodge, 2) Jefferson, 3) Rock and 4) Winnebago. All four are affected by elevated water levels tied to the Rock River system and Lake Koshkonong, both of which have crossed or approached their respective flooding benchmarks in recent days.
Minor flooding can carry real consequences even when it does not reach the levels associated with major flood events. Waterlogged roads, overwhelmed drainage systems and water encroaching on low-lying properties are all common features of minor flooding stages, and conditions can shift quickly if additional rain falls in the watershed.
Where the water stands now
Rock River was last recorded at 9.3 feet, placing it 0.3 feet above the minor flooding mark of 9 feet. The National Weather Service forecasts the river will fall back below that threshold by the morning of Friday, May 8, giving residents in the river corridor a clear timeline for the expected improvement.
Lake Koshkonong presents a slightly more pressing situation. The lake reaches bankfull stage at 9 feet and official flood stage at 10 feet. As of 8 a.m. Tuesday, the lake was sitting at 10.07 feet, just fractionally above flood stage. Forecasters expect the level to ease to 9.9 feet by Wednesday, May 6, with a more significant drop to 9.4 feet projected by Saturday, May 9.
Both waterways are currently classified at minor flooding stages, meaning the immediate risk remains contained. Even so, conditions are active and residents along both systems should continue to monitor water levels and prepare to act quickly if the situation changes.
How to stay safe during a flood warning
Flooding events can escalate quickly, and even minor flooding carries serious risks. Anyone in or near the affected counties should take a few straightforward precautions to protect themselves and their families.
The most important rule is to maintain distance from floodwaters in any form. Just 6 inches of moving water can knock a person off their feet, and roads that appear passable can be deeply deceptive. Most flood-related deaths happen when people attempt to drive through standing or moving water — cars can be swept away in as little as 2 feet of flow, and road surfaces beneath floodwater may be damaged or washed out entirely. If you come to a flooded road, the guidance from emergency officials is clear: turn around and find another route.
Residents should also keep a battery-operated radio or television on hand in case power is disrupted, watch for fire hazards that can emerge unexpectedly during flood events and move to higher ground if water rises near their location. Children should be kept away from any flowing water, which can conceal rocks, fallen trees and debris beneath the surface. Keeping weather notifications active and staying tuned to local emergency updates will ensure the most current information is always within reach as conditions evolve.
Forecasters will continue to monitor Rock River and Lake Koshkonong throughout the week. Residents in Dodge, Jefferson, Rock and Winnebago counties should check for the latest weather alerts and be prepared to respond quickly if conditions worsen before the expected improvement arrives later this week.
Source: Milwaukee Journal Sentinel / National Weather Service